1. Field of the Invention
The invention relates to the laying of sections of pipe and especially laying the sections in a dug trench on a bed of particle material such as gravel. More particularly the field of the invention relates to laying sewer pipe or septic drain pipe in a trench in which it is necessary to align the sections of pipe on a bed of gravel or crushed rock.
2. Description of the Prior Art
When laying sections of pipe in a trench, it is first necessary to dig the trench to a depth below the level designed for the length of pipe. The gravel or crushed rock that provides a bed for the pipe is then filled in the bottom of the trench and the pipe sections are laid upon the gravel. It is understood that the sections must be aligned and often sloped at a fixed angle to provide running of the liquid through the pipe. The process of doing this is quite tedious in that first the gravel is filled into a portion of the trench and a section of pipe is laid on top of it so that the section is aligned with the preceding section. Often additional gravel must be filled in and it is a matter of placement and replacement of a section until the proper amount of gravel is underneath the section to support it in alignment with adjacent sections.
The problem of aligning sections of pipe in a bed of gravel on an individual basis as above described is long recognized and tools have been designed to place and hold the sections of pipe in a fixed predetermined position prior to filling in the bed of gravel or crushed stone. With the sections held in their correct positions the gravel material can then be filled into the ditch below and around the positioned pipe sections while they are being held in place. Examples of such pipe positioning tools are shown in McLaughlin U.S. Pat. No. 3,568,455 and Scott U.S. Pat. No. 4,043,139. The tools of these prior art patents have particular disadvantages that the present invention is designed to conveniently overcome. Both patents disclose pipe positioning tools that are driven into the ground at the bottom of the trench prior to the filling of gravel or other material. A pipe holder is provided that can hold the sections of pipe in a predetermined position for back filling of the gravel. Thereafter it is necessary to release the positioning tool from the pipe and pull it out of the ground for subsequent use. One problem arises from the fact that the tool in the ground must be pulled up through the bed of gravel which is a difficult and inconvenient process. In addition, these pipe positioning tools of the prior art cannot conveniently release the sections of pipe to permit the tool to be withdrawn. The present invention overcomes these and other disadvantages of the prior art pipe positioning tools.